1. Field of the Invention
The invention relates to endoscopic surgical instruments. More particularly, the invention relates to flexible instruments for the transoral invagination and fundoplication of the stomach to the esophagus.
2. State of the Art
Gastroesophageal fundoplication is a procedure for the treatment of gastroesophageal reflux disease (GERD), a condition in which gastric acids are regurgitated into the esophagus resulting in one or more of esophagitis, intractable vomiting, asthma, and aspiration pneumonia. The fundoplication procedure involves wrapping the fundus of the stomach around the lower end of the esophagus and fastening it in place. Traditionally, this procedure is accomplished via open surgery with the use of sutures to secure the plicated fundus of the stomach around the esophagus without penetrating (incising) the stomach. Although traditional fundoplication involves plicating the fundus and the esophagus, as used herein the term includes plicating the fundus to itself near the esophagus.
U.S. Pat. No. 5,403,326 to Harrison et al. discloses a method of performing endoscopic fundoplication using surgical staples or two-part surgical fasteners. The procedure disclosed by Harrison et al. involves performing two percutaneous endoscopic gastrotomies (incisions through the skin into the stomach) and the installation of two ports through which a stapler, an endoscope, and an esophageal manipulator (invagination device) are inserted. Under view of the endoscope, the esophageal manipulator is used to pull the interior of the esophagus into the stomach. When the esophagus is in position, with the fundus of the stomach plicated, the stapler is moved into position around the lower end of the esophagus and the plicated fundus is stapled to the esophagus. The process is repeated at different axial and rotary positions until the desired fundoplication is achieved. While, the procedure disclosed by Harrison et al. is a vast improvement over open surgery, it is still relatively invasive requiring two incisions through the stomach.
U.S. Pat. No. 5,571,116 to Bolanos et al. discloses a non-invasive treatment of gastroesophageal reflux disease which utilizes a remotely operable invagination device and a remotely operable surgical stapler, both of which are inserted transorally through the esophagus. According to the methods disclosed by Bolanos et al., the invagination device is inserted first and is used to clamp the gastroesophageal junction. The device is then moved distally, pulling the clamped gastroesophageal junction into the stomach, thereby invaginating the junction and involuting the surrounding fundic wall. The stapler is then inserted transorally and delivered to the invaginated junction where it is used to staple the fundic wall.
Bolanos et al. disclose several different invagination devices and several different staplers. Generally, each of the staplers disclosed by Bolanos et al. has an elongate body and a spring biased anvil which is rotatable approximately 15 degrees away from the body in order to locate the invaginated gastroesophageal junction between the body and the anvil. The body contains a staple cartridge holding a plurality of staples, and a staple firing knife. Each of the invagination devices disclosed by Bolanos et al. has a jaw member which is rotatable at least 45 degrees and in some cases more than 90 degrees to an open position for grasping the gastroesophageal junction. One of the chief disadvantages of the methods and apparatus disclosed by Bolanos et al. is that the stapler and the invagination device must both be present in the esophagus at the same time. With some of the embodiments disclosed, the presence of both instruments is significantly challenged by the size of the esophagus. In addition, the actuating mechanism of the device disclosed by Bolanos et al. is awkward. In particular, the stapler anvil is biased to the open position, and it is not clear whether or not the stapler anvil can be locked in a closed position without continuously holding down a lever. In addition, it appears that the staple firing trigger can be inadvertently operated before the anvil is in the closed position. This would result in inadvertent ejection of staples into the stomach or the esophagus of the patient.
U.S. Pat. No. 6,086,600 to Kortenbach discloses an endoscopic surgical instrument including a flexible tube, a grasping and fastening end effector coupled to the distal end of the tube, and a manual actuator coupled to the proximal end of the tube. The manual actuator is coupled to the end effector by a plurality of flexible cables which extend through the tube. The tube contains a lumen for receiving a manipulable endoscope and the end effector includes a passage for the distal end of the endoscope. The end effector has a store for a plurality of male fastener parts, a store for a plurality of female fastener parts, a rotatable grasper, a rotatable fastener head for aligning a female fastener part and a male fastener part with tissues therebetween, and a firing member for pressing a male fastener part through tissues grasped by the grasper and into a female fastener part. According to a stated preferred embodiment, the overall diameters of the flexible tube and the end effector (when rotated to the open position) do not exceed approximately 20 mm so that the instrument may be delivered transorally to the fundus of the stomach.
While transoral invagination and fundoplication apparatus and procedures have improved over the years, it is still difficult to deliver and manipulate the necessary apparatus transorally. The primary reason for the difficulty is that the overall diameter, or more accurately the cross sectional area, of the equipment is too large. Notwithstanding Kortenbach's reference to 20 mm, most of the equipment in use today is at least 24 mm in diameter. Moreover, even if the equipment could be reduced to 20 mm in diameter (314 mm2 cross sectional area), it would still be difficult to manipulate. Those skilled in the art will appreciate that larger instruments are less pliable and that the invagination and fundoplication procedure requires that the instruments turn nearly 180 degrees. Moreover, it will be appreciated that large instruments obscure the endoscopic view of the surgical site.
Still other issues which need to be addressed in this procedure include the need to suitably grasp the fundus before plication so that all layers of the fundus are plicated. Preferably, plication damages the fundus so that adhesion occurs during healing.
3. Co-Owned Technology
Previously incorporated application Ser. No. 09/730,911, filed Dec. 6, 2000, entitled “Methods and Apparatus for the Treatment of Gastric Ulcers”, discloses a surgical tool which is delivered to a surgical site over an endoscope rather than through the working lumen of an endoscope.
Co-owned provisional application Ser. No. 60/292,419, filed May 21, 2001, entitled “Methods and Apparatus for On-Endoscope Instruments Having End Effectors and Combinations of On-Endoscope and Through-Endoscope Instruments”, discloses many tools and procedures including an on-scope grasper assembly having grasping jaws, and a through-scope clip applier having jaws adapted to close about tissue and apply a clip over and/or through the tissue. In operation, the grasper jaws may grab and hold tissue, e.g., the fundus of the stomach or esophageal tissue, while the jaws of the clip applier surround a portion of the tissue held by the grasper jaws and apply a clip thereover.
Previously incorporated application Ser. No. 09/891,775, filed Jun. 25, 2001, entitled “Surgical Clip”, discloses a surgical clip having a U-shaped configuration with first and second arms, and a bridge portion therebetween. The first arm is provided with a tip preferably having a catch, and the second arm extends into a deformable retainer having a tissue-piercing end and preferably also a hook. During application, tissue is clamped, and the clip is forced over the clamped tissue and the retainer of the second arm is bent and may be pierced through the tissue. The retainer is toward and around or adjacent the tip of the first arm preferably until the hook is engaged about the catch to secure the clip to the tissue and prevent the clip and tissue from separating. The clip is provided with structure that facilitates the stacking of a plurality of clips in a clip chamber of a clip applier.
Previously incorporated application Ser. No. 09/931,528, filed Aug. 16, 2001, entitled “Methods and Apparatus for Delivering a Medical Instrument Over an Endoscope while the Endoscope is in a Body Lumen”, discloses methods and apparatus for delivering a medical instrument over the exterior of an endoscope while the endoscope is installed in the patient's body in order to allow the use of instruments which are too large to fit through the lumina of an endoscope.
The previously incorporated simultaneously filed application entitled “Flexible Surgical Clip Applier”, discloses a surgical clip applier having a pair of clip applying jaws at the distal end of an outer coil, a set of pull wires extending through the outer coil and coupled to the jaws, and a push wire extending through the outer coil. A clip chamber is provided in the distal end of the coil. A clip pusher is provided at a distal end of the push wire, and adapted to advance a clip into the jaws. The jaws include clamping surfaces which operate to compress tissue between the jaws when the jaws are closed, channels in which a distalmost clip rides when the jaws are closed and the pusher is advanced thereby causing the distalmost clip to be pushed over the tissue, and distal anvil portions which operate to bend a portion of the distalmost clip to facilitate its retention on the clamped tissue. The clip applier is capable of providing a pushing force far in excess of a perceived possible maximum of the 200 grams (0.44 lbs) published in the art. One embodiment of the device of the invention provides a pushing force in excess of 2267 grams (5 lbs).